In order to be able to attach thermally loaded pipes permanently to a carrier, it is customary to fasten the respective pipe to a fixed bearing, on the one hand, and to a freely moving bearing, on the other hand, on the respective carrier so that the length of the pipe relative to the carrier can change without unacceptably high stresses occurring between the pipe and the carrier. In order to implement such a freely moving bearing, what are referred to as sliding fit arrangements can be used in which the pipe is seated in a receptacle opening which is formed in the respective carrier, said pipe being specifically seated in such a way that it is axially adjustable, in terms of its longitudinal axis, in relation to the carrier.
Thermally loaded pipes which are mounted on a carrier component by means of a sliding fit are used in many technical fields, predominantly where hot or cold fluids are transported in pipes. For example, this set of problems occurs in heating systems, cooling systems and exhaust systems. Exhaust systems are found in heating devices and in internal combustion engines, preferably in motor vehicles. For example an exhaust gas treatment device can contain at least one pipe which is mounted in a housing of the exhaust gas treatment device using such a sliding fit. An exhaust gas treatment device may be, for example, a particle filter, a catalytic converter or a sound damper or any desired combination of such devices.
A conventional sliding fit can have a certain degree of radial play between the pipe and the respective receptacle opening in order to facilitate the axial adjustability of the pipe in the fit. This is unfavorable for applications which require a certain degree of gas-tightness since it is basically possible for gas to be exchanged through the sliding fit. In particular in the case of an exhaust system, it is necessary to prevent exhaust gas from escaping into the surroundings, for example through a sliding fit, in view of more stringent regulations relating to environmental protection.
In addition, in conventional sliding fit arrangements there is basically the problem of comparatively high mechanical loading of the pipe or of the respective carrier part within the sliding fit. Mechanical loading is associated with wear and can lead to disruptive generation of noise.